River crab farmers clear their ponds for better farming next year; pond-clearing drugs must not be used indiscriminately

In many small ponds the crabs are almost all sold, and pond clearing is coming up. How to clear the pond correctly and master the methods well, to set the stage for next year's farming, is crucial! Question? Across the whole Xinghua area everyone generally stocks 1000 crabs/mu, so why after maturity are only about 500 recaptured? Many farmers are puzzled: throughout the whole farming process they never saw dead crabs, so where did the remaining 500 crabs go? This is worth investigating deeply! Reasons for the residue? Wrong time for releasing seedlings? Wrong time and method for planting grass? Why is the yield so low? So today let us discuss how pond clearing can avoid residues! Next we will update when to plant grass and when to release seedlings, please stay tuned. Common pond-clearing drugs

1: Pyrethroids: the variety with the largest market usage, small-bottle packaging divided into (deltamethrin, fenpropathrin, cypermethrin), not worth recommending to everyone; using too much of this will definitely affect next year's survival rate! No doubt about it

2: Trichlorfon: for ponds with ring-leg disease, some people will choose to use it, but everyone has a misunderstanding, saying that lime cannot be used after using trichlorfon, which is wrong,

1. Using trichlorfon and lime at the same time will produce dichlorvos; remember it is at the same time; if not at the same time, with an interval of one week there is no problem

2. Dichlorvos is extremely unstable in water and hydrolyzes very easily, so there is no residue, everyone can rest assured

3: Bleaching powder (chlorine preparation, strong sterilization and disinfection effect, no residue, 50 jin per mu)

4: Saponin, yellow vine, tea seed cake (kills fish but not shrimp or crabs)

5: Quicklime, some farmers directly apply 100 jin of lime per mu without using other drugs

Pond clearing has techniques

1: Ponds with many crayfish: use the pyrethroid cave-flooding method, block them up, remember that soaking the pond on a large water surface will affect next year's seed survival rate